audit: inline audit_syscall_entry to reduce burden on archs

Every arch calls:

if (unlikely(current->audit_context))
	audit_syscall_entry()

which requires knowledge about audit (the existance of audit_context) in
the arch code.  Just do it all in static inline in audit.h so that arch's
can remain blissfully ignorant.

Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/arch/sh/kernel/ptrace_64.c b/arch/sh/kernel/ptrace_64.c
index ba720d6..3d0080b 100644
--- a/arch/sh/kernel/ptrace_64.c
+++ b/arch/sh/kernel/ptrace_64.c
@@ -536,10 +536,9 @@
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->regs[9]);
 
-	if (unlikely(current->audit_context))
-		audit_syscall_entry(audit_arch(), regs->regs[1],
-				    regs->regs[2], regs->regs[3],
-				    regs->regs[4], regs->regs[5]);
+	audit_syscall_entry(audit_arch(), regs->regs[1],
+			    regs->regs[2], regs->regs[3],
+			    regs->regs[4], regs->regs[5]);
 
 	return ret ?: regs->regs[9];
 }